FIG. 1 is a perspective view of a prior art paper binding device 10 configured to hold a plurality of paper sheets together utilizing aligned holes formed in each of the plurality of sheets. The paper binding device includes a first part 12 and a second part 14. FIG. 2 is a sectional view of the structure of FIG. 1 taken along lines 2-2 and FIG. 3 is a sectional view of the structure of FIG. 1 taken along lines 3-3. FIG. 4 is a perspective view of the prior art paper binding device of FIG. 1 now in a partially closed position where the two outer bendable extensions are locked in their respective channels.
The first part 12 includes a first elongated strip elongated along a first longitudinal direction 16. A first cross-section through the first elongated strip 12 perpendicular to the first longitudinal direction 16 has a first outer perimeter shape which includes at least one flat first surface 18. A plurality of bendable extensions 20 extend from the at least one flat first surface 18, wherein the plurality of bendable extensions 20 are spaced along the first longitudinal direction. The plurality of bendable extensions 20 extend perpendicular from the at least one flat first surface 18 to each of their respective distal ends.
The second part 14 includes a second elongated strip elongated along a second longitudinal direction 22. A second cross-section through the second elongated strip perpendicular to the second longitudinal direction 22 has a second outer perimeter shape which includes at least one flat second surface 24, which is the underside of part 14 as shown in FIG. 1. A plurality of through apertures 26 are disposed from the at least one flat second surface 24 through to an opposite surface 28. The plurality of through apertures 26 are matched to the plurality of bendable extensions 20 when the first and second parts are mutually aligned to another along the same first and second longitudinal directions. A plurality of elongated channels 30 are openly formed in the opposite surface along the second longitudinal direction, wherein each elongated channel of the plurality of elongated channels starts at its respective through aperture 26 and extends to a respective channel end 32. Each elongated channel comprises a channel opening 34 along the opposite surface which is smaller than a widest portion of the channel 36 disposed within the second elongated strip.
When the at least one flat first surface 18 is disposed facing the at least one flat second surface 24 and the plurality of bendable extensions 20 are fitted through the plurality of through apertures 26, the plurality of bendable extensions are configured to be manipulated by a user to bend and lock into the plurality of elongated channels as shown in FIG. 4. In this figure, the two outer bendable extensions 20 have been bent over by the user and they have then locked into their respective channels. In this way the papers that would be between the two flat surfaces would be fully captured and bound.
One of the problems with the prior art designs is that the hole spacing is not conducive to using pre-punched paper sheets that come in standard hole spacing and sizes. Typically, the prior art designs utilize hole spacing that are not standard and require special paper punching tooling to create the holes to begin with. Furthermore, the prior art designs are weak in that they don't properly hold paper together under rigorous use. This is because the bendable posts are too thin and don't properly bind the papers in a secure manner. Accordingly, there is a need for an improved design that overcomes these problems. The present invention fulfills these needs and provides other related advantages.